Define, 1) Newtonian Fluid, 2) Bingham plastic, 3) viscoelastic fluid
[3 marks]Write a short note on Residence and Relaxation Times
[4 marks]Which are the different Mathematical Models available for Viscoelastic Behavior? Explain any one in detail.
[7 marks]Describe Fourier number and temperature gradient
[3 marks]State and explain Power law.
[4 marks]Explain the Rheological model for polymer melt flow
[7 marks]Explain Enthalpy calculations for Injection moulding
[7 marks]Write a short note on thermal conductivity on Plastics.
[3 marks]Explain the radius of gyration of linear ideal chain
[4 marks]Explain the radius of gyration of an ideal branched polymer( kramers theorem)
[7 marks]Derive the equation for Temperature Rise in Die, ∆T = Pwhere 𝜌 is the 𝜌Cp density of the fluid and Cp is its specific heat.
[3 marks]Explain Heat Transfer Phenomena in Plastic Processing.
[4 marks]Write a short note on radius of gyration of rod polymer.
[7 marks]Write a short note on strength of composites for Fiber reinforced materials.
[3 marks]Write a short note on Creep.
[4 marks]Describe Mathematical Models of Visco-elastic Behavior through Maxwell model.
[7 marks]Discuss the Stress Strain behaviour of plastic materials.
[3 marks]Write a short note on Isometric and Isochronous graphs with neat sketch.
[4 marks]Explain Kelvin Voigt Model.
[7 marks]Define Drag flow, Pressure flow and Leakage flows.
[3 marks]The density of a composite made from unidirectional glass fibers in an epoxy kg matrix is 1950 ⁄ . If the densities of the glass and epoxy are known to be m3 kg kg 2540 ⁄ and 1300 ⁄ ,Calculate the weight fraction of fibers in the m3 m3 composite.1
[4 marks]Asingle screw extruder is to be used to manufacture a nylon rod 5 mm in diameter at a production rate of 1.5 ndmin. Using the following information, calculate the required screw speed. Nylon Extruder Die Viscosity = 420 Ns/m2 Diameter = 30 mm Length = 4 mm Density (solid) = 1140 Length = 750 mm Diameter = 5 mm kg/m3 Density (melt) = 790 Screw flight angle = kg/m3 17.7" Metering channel depth = 2.5 mm Die swelling effects may be ignored and the melt viscosity can be assumed to be constant.
[7 marks]Discuss the analysis of Blow moulding operation,
[3 marks]Apolyethylene injection moulding is in the form of a flat sheet 100 mm square and 3 mm thick. If the melt temperature is 230°, the mould temperature is 30° and the plastics may be ejected at a centre line temperature of 90° estimate
[4 marks]The temperature of the material at the centre of the moulding after seconds.
The time taken for the centre of the moulding to reach the ejection temperature of 90° Take temperature gradient 0.58 and fourier number 0.59 & 𝛼 = 1×10−7 m2 ⁄ s.
[ marks]Ablow moulding die has an outside diameter of 30 mm and an inside diameter of 27 mm. The parison is inflated with a pressure of 0.4 MN/m2 to produce a plastic bottle of diameter 50 mm. If the extrusion rate used causes a thickness swelling ratio of 2, estimate the wall thickness of the bottle. Comment on the suitability of the production conditions if melt fracture occurs at a stress of MN/m2
[6 marks]